Propelling unit for trucks



II 9, H949. 1 SCHRECK I 2,478,327

PROPELLING UNIT FOR TRUCKS Filed Aug. 3. 1944 4 Sheets-Sheet l INVENTOR. in F Schreck jfl/M 5. gi/ulm l: I II I Irv ATTORNEY Aug. 9, 1949. l. F. scHREcK PROPELLING UNIT FOR TRUCKS 4 Sheets-Sheet 2 Filed Aug. 3. 1944 INVENTOR. F., Sels/reak yam/g s. M

ATTORNEY Irvin. BY

Aug 9, 1949. l. F. SCHRECK 2,478,327

PROPELLING UNIT FOR TRUCKS Filed Aug. 3. 1944 4 Sheets-Sheet 5 l INVENTGR. v Irvin, F. Schreck ATTORNF' 9, H94. 1. F. scHREcK 2,478,327

PROPELLING UNIT FOR TRUCKS Filed Aug. 3. 1944 4 Sheets-Sheet 4 Patented Aug. 9, 1949 UNITED STATES PATENT FFICE 2,478,327 PROPELLING UNIT FOR TRUCKS Irvin F. Schreck, Cleveland Heights, Ohio Application August 3, 1944, kSerial No. 54.7;930

3 Claims.

The present invention relates to trucks of the type disclosed in my Patent 2,209,356, granted July 30, 1940, in which a swiveled propelling unit is employed which has a draft tongue by means of which the truck may be steered by the operator while being propelled by the motor, which may be used, when desired, to move or assist in moving the truck and which carries manually operable motor controlling elements.

One object ofthe present invention is to provide a means `for automatically opening the motor circuit to render the control mechanism ineffective whenever the draft tongue is moved to an upright position.

A further object of the invention is to provide arreversible electric motor and motor-controlling switches so arranged and combined that the motor windings cannot be damaged by short circuits in the wiring extending to the controlling switches.

A further object is to provide a compact and propelling unit of rugged and durable construction that 4may be quickly and easily assembled and having all parts easily accessible for replacement or repair.

Further objects are to provide motor-controlling switches that are conveniently accessible andlreadily detachable and to provide connections from a battery on the truck frame to solenoid operated motor-controlling switches on the propelling unit and from the solenoids to controlling switches on the draft tongue.

Additional objects are to provide means by which overheating of the motor is prevented and to provide means for `adjusting the motor with respect to the traction wheel to apply the proper tension to the Wheel drive chain.

With the above and other objects in view, the invention may belsaid to comprise the truck as illustrated in the accompanying drawings, hereinafter described and .particularly set forth inthe appended claims, together with such variations and modicatons thereof as will be apparent to one skilled in the art to which the invention pertains.

Reference should be had to the accompanying drawings forming a part of thisspecication, in which:

Figure 1 is a side elevation ,of the forward end of a truck embodying the invention;

Fig. 2 is a front elevation of the truck;

Fig. 3 is a top ,plan View of the forward portion of the truck;

Fig. 41s a sectional view showing the motor controldevices mounted on the `draft tongue;

Fig. 5 is a fragmentary vertical section show- .ing the hinge mounting of the cover;

Fig. 6 is a fragmentary side elevation on an enlarged scale, with portions of the truck and propelling unit frames broken away to show parts that would otherwise be concealed;

Fig, 7 vis a fragmentary side elevation showing the `brake vin wheel-engaging position;

Fig. 8 is a fragmentarydetail View showing the latch for holdingthedraft tongue in upright po.- sition in side elevation;

Fig. 9 is a front elevation on an enlarged scale, with -a portion of the frames of the truck and propelling unit in section;

Fig. 10 is a horizontal section taken on the line indicated at lll-,i0 in Fig. 6;

Fig. V1;1 is a vertical section taken on the line indicated at lI-YH in Fig. 6;

Fig. 12 .is a fragmentary horizontal section taken on .the line `indicated at v|2I2 in Fig. 11; Fig. 13 is a vertical section taken on the line :indicated at |3-.-|3 .in Fig. 11;

Fig. 1.4 is-a rearelevation of the Ysolenoid operated motor-controlling switch;

Fig. 15 is laside elevationof the switch with a portion brokenaway and shown in section;

Fig. `16 is a front elevation of the switch, viewed -asindicated at 16a-.i6 in Fig. 15;

Fig. 17 is 4a bottom plan view of the switch viewed as indicated at .I l--H -in Fig. 15;

Fig. 1 8 Yis a .sectional yelevation illustrating the action of the switch; and

Fig. 19 is a wiring diagramshowing the motorcontrolling circuit-s.

In the accompanying drawings, the invention is shown applied to a low-bodied truck of the lift type, such .as is commonly used for transporting loading skids from place to place infactories or warehouses. The forward portion of a truck frame yl vtogether-with the rear end portion of a load vcarrier `2 are `shown in the drawings, the present invention being concerned primarily with the steering mounted at `the forward end of the ltruck frame.

The truck cframe I is provided at its forward end 4with .an annular an annular .propelling is rotatably mounted.

Asbest shown in Figs. `6 and 9 -the forward end of the .truck trame I is supported upon the propelling unit frame .4 by a ball bearing 5 interposed betweenaninternalshoulder 6 on the bearing member 3 and an .external shoulder 1 on .the annulus `ll at its lower edge. At diametrica-lly opposite points on the bottom edge .of the annu- .unit supporting framed and propelling unit that isi Abearing Aportion 3, in which lus 4 bearing members 8 are mounted. Shims 9 are interposed between the bearing members 8 and the bottom of the annulus and the bearing members Il are secured to the annulus by means of bolts I0. A set screw II is threaded in each of the bearing members 8 centrally thereof and bears against the underside of the annulus 4. The bearing members 8 support the opposite ends of an axle I2 and may be adjusted vertically by loosening the bolts I and adjusting the set screws II. A traction wheel I3 is mounted on the axle I2 and the frame of the propelling unit has a horizontal cross member I4 positioned above the wheel directly over the axle and has its opposite ends integrally connected to the annulus 4.

The cross member I4 provides a support for a motor housing i5 which has an integral hollow pedestal I6 that serves as a switch box, and provides a support for a motor housing I5. The housing I5 is preferably mounted with its axis parallel with the axle I2 and is provided with an end wall I1 that is spaced from the pedestal I6 and extends down to the cross member I4. The end wall I1 has an integral, outwardly projecting, annular flange I9 and provides a recess I9 at one side of the pedestal I6. A circular cap 29 is secured to the ange I8 to provide a gear housing at the end of the motor casing. A shaft 2| is journaled in a bearing 22 disposed centrally of the cap 2l) and in a bearing 23 mounted in the motor housing adjacent the top of the pedestal I6. An internal gear 25 is fixed to the shaft 2I within the gear housing and meshes with a gear 26 on the shaft 21 of an electric motor 28 mounted in the housing I5. The shafts 2I and 21 are parallel with the axle I2 and the shaft 2I has a sprocket 29 xed thereto and positioned in the recess I9. A drive chain 30 extends over the sprocket 29 and over a sprocket 3l on the wheel I3. The motor 2B drives the wheel I 3 through the gears 26 and 25 and through the sprocket chain 30, and proper tension may be applied to the chain 30 by adjusting the bearings 8 with respect to the annulus 4.

An electric storage battery 32 is mounted on the forward end portion of the truck frame i immediately to the rear of the bearing portion 3, the battery 32 being mounted in angle bar seating members 33 secured on the frame and suitable means, which will hereinafter be described in detail, are provided for conducting current from the battery to the motor 21. A cover 34 having a rear portion 35 overlying the battery 32 and a forward portion 36 overlying the propelling unit is supported on the truck frame by means of vertical sleeves 31 rigidly attached thereto at opposite sides thereof that are slidable on tubular upright posts 38 attached to opposite sides of the frame I immediately adjacent the bearing member 3. One of the posts 39 has an extension in the form of a round bar 39 fitting therein and having a ange 40 that rests on the top of the post. The bar 39 provides a pivot on which the cover 34 may be swung to a position at one side of the truck, clear of the battery and propelling unit, as shown in dotted lines in Fig. 2, when it is desired to obtain access to these members.

A suitable draft tongue 4I is connected to the annulus 3 by a horizontal pivot 42 disposed forwardly of and below the cross member I4, the pivot 42 being parallel'to the axle I2. The draft tongue 4I can be swung upwardly to a substantially upright position in front of the motor casing I5 and carries a lug 43 on its underside which two contact members 59.

engages with the annulus 4 to limit its downward movement. The tongue 4I has a bracket 44 adjustably attached thereto adjacent the pivot 42 by means of bolts 44a extending through a slot 44h in the bracket 44 shown in Fig. 3 and this bracket carries a laterally projecting pin 45 that engages in a slot 46 formed in an arm 41 projecting upwardly from a brake shoe 48. When the draft tongue 4I is in the position shown in Fig. 6, the brake shoe 48 is supported by the pin 45 in a position clear of the wheel I3. When the draft tongue 4I is swung to an upright position, as shown in Fig. 7, the shoe 48 is lowered into engagement with the wheel I3 and the pin 45 engages the lower end of the slot 46 to press the brake shoe against the wheel. During the operation of the truck, the handle 4i is normally supported in the position shown in Fig. 6, but if the truck travels faster than the operator, the backward pressure exerted by the operator on the outer end of the tongue will swing the handle to upright position and the brake will be applied.

Means is also provided for automatically opening the motor circuit to stop the motor when the tongue 4I is moved to upright position.

As shown in Figs. 1, 6 and 9, a switch casing 49 is mounted upon the top of the motor housing I5. The casing 49 is of cylindrical form and is positioned with its axis disposed transversely with respect to the motor shaft and the wheel axle. As best shown in Fig. 10, terminals 59 are secured at diametrically opposite points to the wall of the cylindrical casing 49, the terminals 5I) being insulated from the casing 49 by collars 5I of insulating material. A suitably insulated wire 52 connects one of the terminals 50 to the battery 32 and an insulated wire 53 extends from the 0pposite terminal 5U to the pedestal I6. The terminals 50 are spaced laterally from the central ver- L tical axis of the propelling unit and in order to protect the end of the wire 52 attached to the terminal 50 against twisting strains, an eyelet 54, which has an opening of a size but slightly larger than the insulated wire, is xed to the top of the casing 49 substantially at the vertical axis of the propelling unit, so that the flexing of the wire 52 during the swivelling movements of the propelling unit is conned to the portion of the wire extending from the eyelet 54 to the battery.

An axially movable plunger 55 is mounted in the casing 49 and carries spaced disks 56 and 51 that have a sliding t in the casing and in the plunger. A coil spring 58 is interposed between the disks 56 and 51 and this spring presses the rear disk 56 against a disk 59 of insulating material that engages the contact members 50. The forward disks 51 is held by the spring 58 against a nut 60 on the plunger. By adjusting the nut G0 the tension of the spring 58 may be adjusted. The rear end of the plunger 55 carries a collar 6I of insulating material that is clamped to the plunger and which carries a contact disk 52 of conductive material that is adapted to engage the The spring 58 serves to normally hold the plunger 55 in its forward position with the contact disk 62 in circuit closing position in engagement with the contact members 50. The plunger 55 is positioned in the path of movement of the draft tongue 4I and has an adjustable abutment member 64 threaded on its forward end that is engaged by the draft tongue 4I as the tongue approaches its upright position to move the plunger 55 rearwardly and shift the contact disk 62 out of engagement with the contact members .511. ilhe actuation :of .the plunger .'55 serves :to break the :motor ,circuit so that lItheirnotor stops substantially simultaneously with ithe application of the .brake. lEllhe .draft tongue fail :preferably 4,is :latched ein `its upright position to hold 'the :motor circuit .open and to apply the brake during :intervals when the truck is 'not `-in ruse, .a fsuitahle ila'tch :65 being '.prouided on fthe propelling funit `which .engages with :a laterally projecting lug `iia on the draft tongue, asfs'hown inllig.@faiths/drawing.

shown 2in Fig. '11, the motor fhousing |15 provided :with :a 'fbearing ft for the ,motor sha-tt 251, .which supports -rthe .shaft adjacent the gear 2-6. .Adjacent .the opposite end of fthe ihousina.

the rshattis supported `by a: secondfbearing f 6?! that is 'mounted in a :spider ies that' :provides supports for brushes l69 o'f .a commutator on the'shaft 2W. The -shart 12d 4has a -reduced :end .extending past the `loeiarirrgfl -to which afan 11| iisrattached. The Jcomiriutator 4and fan are-enclosed rby:afsheet metal housing member r1.2 that forms .an extension df the housing I 5, lthe housing .member 1.2 being sof cylindrical 1form with :a closed `end :and

an axially extending opening at the bottomitheres I of. The Fhous'ing '122 fis :clamped :on the spider `68, the sheet ametal body 'thereof fleeing :provided :with extending arms T3 :at opposite edges :of the 1bottom Vopening `that .fare :connected by clamping bolts ian arcuate sheet :metal :plate "68a :is attached 'to *the spider 68 and lforms an inner Jian casing -`wall partitioning the :lower half of :the fan yfrom theinner portion -of the housing i112 and causing air to enterfth-eiupper portion o'f fthe fan and to 'be discharged ldownwardly through lthe bottom fopen'ing. iSuction 4created '-by `the. lfan "H draws Asome air ythrough the lbottom yopening of the 'housing 112 land `Aupwardly faround the 'commutator "l to the Lupper portion `:ofthe fan. .Ad-

jacent the opposite end thereof .the housing t5 is provided with openings 15 to the recess $9,130 that lduring operation of the motor the fan H also draws air upwardly through the openings l and laterally through the space between the armatureand :lield windings ofthe 1motor '.28 and over the commutator 70, discharging 4fthe air downwardly through the peripheral opening at the bottom of lthe housing member "12. The motor is v.thus eiectively cooled v.during operation.

.YI-Ihegearhousing formed between theend wall ll .of thehousing "i5 andthe cap2l is preferably sealed .to lretain lubricant, an oilsealingingi'l being provided in 'the wall of 'the housing 'P inwardly ofthe bearing'andfa second oilsealing ring `being `provided -on the -shaftiZfl in the fopeningthroughthewall H The lhollow pedestal 6 -is vof rectangular cross sectionend isvopen atthe rear side to providefa compartment Ain Awhich a, .motor-controlling switch :may :be Aremovahly mounted. Theunntorcontrolling :switch .is .in the Aform :of a unit that may be .inserted into or yremoved. ffrom. ,pedestal I6 and as shown in Figs. 14 to 18, inclusive, the switch is mounted upon an insulating block 18 which is of a size to fit Within the pedestal I6.

The block 18 has a pair of solenoids 19 mounted side by side with their axes vertical upon the top thereof and is provided with slots 89 through which the armature 8| of the solenoids 19 extend. An angle-shaped contact member 82 extends across the insulating block 'I8 and upwardly along the rear side thereof, the upwardly extending portion of the contact member 82 being provided with an integral terminal post 83 that projects laterally therefrom. The post 83 is threaded and passes ithrough an aperture in a 'closure-.member 84 formed of insulating :material that .is of .a size to close Zthe open rside :of l'the :pedestal 126. The closure member 821 fis :clamped against the block 18 land theicontactmember S82 `by .means of anut 85 on the fterminal post 83. The .terminal vpost 83 provides :aiconnection `for the rlower -endof CAthe wire5'3 `'that extends downwardlyfrom the safety switch IIS-on'top ofthe motor housing. AAttached tothe insulating'block'lonithe front sideftheren of, 4:there is asocket member -86 .of .insulatingmae terial lthat has a :threaded portion :extending through -an lopening in the Vfront wall of .the pedestal I6, the socket member being clamped ito the drontvwall vby means of .amut .'87, as .shown in Fig. 6. 4The:socket.llt has terminals di! .and $9 that areconnectedfto conductors vandrl `.that extend toterminals .of the lsolenoids 19.

-A A4contact disk 92 iis yieldably mounted `upon each of the solenoid armatures itil, :the'disks :92 being yieldably supported on the armatures the tween iupperdind flower coil springs 93 and 9.4. The contact disks :921serve to 'connect the .-main contact V'member 1.8:2 with leither f of -two auxiliary. contact r-rnembers "w55 :extending .across the bottom of fthe 4insulating block 18 at `opposite ends thereof. The :Contact membeI :95 have-eclarnpingterminais 9S `which V,connect the contacts 95 with conductors .91 l.leading to -eld :windings of :the motor 2.8, monta-cts 92 serving .to direct .current to one or the V.other vof two motor windings .arranged to drive the imotor 23 in opposite direc-- tions.

Itg-is :desirable that .-means :be provided toprevent simultaneous supply of current lto both the forward and vreverse `:field iwindings and means :.is, therefore, Il.provided for 4preventing Ythe engagementof bothicontact disks 9,2 with l.the 'contacts 9.5:in theevent that 4bothfsolenoids .1 9 should .be simultaneously energized due to a short A`circuit or other cause. To prevent such simultaneous engagementfthe two, disks 2r engage with arocker plate :98 positioned ,beneath the contact .memher ;82 byholts SSiextending .downwardly-through the rinsulating block 1li, thebolts beinganchored to -a .plate .L08 supported .upon .the tops of the solenoids ..19 andxextending through :openings .I lll inthe plate .98 .that aredarge enough to ipermit a limited `rockingmovementof the plate 8.8. The Dlatel .is .insulated .from .the .bolts .99 by means of insulatingsleeves Miron thelowerends of the bolts. The 4plate 98 contacts with the undersurfaceof .the-contact member .S2 and isalso conductivelyjoned Yto the .plate 82 by means of a pigtail i113.

The .contact disks 92 are positioned 'by arl arched retaining plate '|1534 supported by the bolts 99 at their lower ends, that has end portions .in engagement .with the undersides Yof said disks to ensureproper engagement ,ofV the disks with 'the rocker plate 98. Actuation of' one of the solenoids causes oneof the disksz .to be drawn 'up- Wardlyintoengagement with one of the vContact members 95 while the rocker plate J93 'is vrocked upon the center Contact plate 82 to press the other disk 92 downwardly away from the contact member 95 at the opposite end of the block 18. One of the contact members is thus positively held out of engagement while the other is engaged. Should both solenoids be simultaneously energized, the rocker plate 98 serves to hold both contact disks 92 out of engagement with the contact strips 95 so that the forward and reverse windings of the motor cannot be simultaneously energized.

The socket 86 that projects through the front wall of the pedestal I6 is adapted to receive a plug |05 carried by insulated wires |06 that eX- tend into the draft tongue 4| adjacent the pivot as shown in Fig. 6. The draft tongue is preferably tubular so that the wires |09 may extend within the tongue into the outer end thereof. Adjacent the outer end of the draft tongue two oppositely disposed switches |01 and |08 are provided. These switches are normally open and are provided with plungers which are movable to close the switches. As shown in Fig. 19, these switches are so connected to the wires that each of the solenoids 19 is controlled by one of the two switches.

The draft tongue 4| is provided at its outer end with a laterally projecting handle provided with a rotatable sleeve ||0, which carries a lever I Il attached to a cover plate ||2 that extends over the switches |08 and |09 and. has slidable engagement with the tongue 4|. The member ||2 has a downwardly projecting end portion ||3 that is adapted to engage with the plunger |09 of the switch |07 and adjacent its outer end has a downwardly projecting member ||4 that is adapted to engage with the plunger |00 of the switch |08. When the lever is swung forwardly, the end member ||3 of the cover ||2 engages with the plunger |69 of the switch |01, closing the circuit of the solenoid E9 that controls the motor winding that causes the motor to be driven in a direction to propel the truck in a forward direction. When the sleeve ||0 is turned in a direction to move the lever rearwardly, the switch |08 is closed to cause the truck to be propelled in a rearward direction.

1t is to be understood that variations and modifications of the specic device herein shown and described for purposes of illustration, may be made without departing from the spirit of the invention.

What I claim is:

l. In combination with a truck having a frame, a propelling unit swiveled to said frame, said propelling unit comprising a frame having an electric motor mounted thereon, a wheel beneath said motor, a driving connection from the motor to the wheel, a draft tongue pivoted to the frame of the propelling unit forwardly of and below the motor to swing about an axis parallel to the axis of the wheel, said tongue being movable to a substantially upright position in front of the motor, a circuit for said motor, a normally closed switch in the motor circuit, and a circuit breaker including a member mounted upon the top of the motor casing for movement in a direction transverse to the wheel axis, said member having an adjustable forward end portion in the path of said tongue.

2. In combination with a truck having a frame with an annular bearing member at its forward end, a propelling unit comprising an annulus adapted to be rotatably mounted in said annular bearing member, an axle mounted in said annulus, a wheel on said axle, a support extending across the annulus above the wheel and connected at its ends to the annulus, an electric motor having a casing with a hollow pedestal mounted upon said support, a driving connection from the motor to said wheel, a draft tongue pivoted to the annulus below the motorand forwardly thereof to swing about an axis parallel to said axle, a battery on the truck frame adjacent the propelling unit, a circuit for said motor including a normally open controlling switch mounted in said pedestal and a normally closed safety switch mounted upon the top of the motor casing, a conductor extending from the battery to the safety switch and a conductor from the safety switch to said controlling switch, a solenoid in the pedestal for actuating the controlling switch, a solenoid circuit including wires extending from the solenoid to the draft tongue adjacent its pivot, a manually operable switch on the draft tongue adjacent its forward end for controlling the solenoid, and a member movably mounted on the motor casing and positioned to be engaged by the draft tongue as it approaches an upright position for opening said safety switch.

3. In combination with a truck frame, a propelling unit having a frame swiveled in the truck frame to turn about a vertical axis, the swiveled frame having a horizontal supporting member, a traction wheel mounted in the frame beneath said supporting member, an electric motor having a casing with a hollow pedestal mounted on said supporting member, a motor controlling switch mounted in said hollow pedestal and having an actuating solenoid, a socket in a wall of said pedestal and wires connecting the solenoid to the socket, a draft tongue pivoted to said swiveled frame to swing vertically, a manually operable switch on said tongue and wires connected to said switch and to a plug engageable with said socket.

IRVIN F. SCHRECK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

